Conventionally, a polyvinyl chloride resin composition is generally used as an insulator of a low-voltage electric wire for an automobile since the resin is excellent in flame retardancy and chemical resistance. Recently, demand for thinning of an insulator of an electric wire and reduction of a diameter of the wire is rising increasingly to meet a requirement of using a limited space in an automobile effectively.
An electric wire having a reduced diameter has a problem that when a terminal of the wire is inserted into a connector, the insertion is made difficult by buckling of the wire. To solve the problem, the present applicants previously proposed an insulated electric wire including an insulating material having a flexural modulus of larger than 2.0 GPa (see PTL 1).